PARP (Poly ADP Ribose Polymerase) is an enzyme existing in nuclei of cells of various organs, and is believed to be involved in repair of DNA strand break. As a compound having PARP inhibitory activity (hereinafter, also referred to as “PARP inhibitor”), various compounds have been reported heretofore, and for example, in WO 02/48117 A (Patent Document 1), WO 03/055865 A (Patent Document 2), and WO 03/063874 A (Patent Document 3), plural compounds are disclosed, and these compounds are suggested to have the potential to become therapeutic agents for many diseases.
In recent years, PARP inhibitors attract attention as novel anticancer drugs, and Annals of Oncology, 22, 268-279 (2011) (Non-Patent Document 1) describes that plural PARP inhibitors are under development as anticancer drugs.
Further, WO 2009/041565 A (Patent Document 4) and WO 2009/041566 A (Patent Document 5) respectively describe prophylaxis or therapy of keratoconjunctive disorder and posterior ocular disease by a PARP inhibitor.